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Oropouche virus is the aetiological agent of Oropouche fever, a zoonotic disease mainly transmitted by midges of the species Culicoides paraensis. Although the virus was discovered in 1955, more attention has been given recently t...
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Oropouche virus is the aetiological agent of Oropouche fever, a zoonotic disease mainly transmitted by midges of the species Culicoides paraensis. Although the virus was discovered in 1955, more attention has been given recently to both the virus and the disease due to outbreaks of Oropouche fever in different areas of Brazil and Peru. Serological studies in human and wild mammals have also found Oropouche virus in Argentina, Bolivia, Colombia, and Ecuador. Several mammals act as reservoirs of the disease, although the sylvatic cycle of Oropouche virus remains to be assessed properly. Oropouche fever lacks key symptoms to be differentiated from other arboviral febrile illnesses from the Americas. Sporadic cases of aseptic meningitis have also been described with good prognosis. Habitat loss can increase the likelihood of Oropouche virus emergence in the short-term in South America. (c) 2017 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.
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Oropouche virus, of the family Bunyaviridae, genus Orthobunyavirus, serogroup Simbu, is an important causative agent of arboviral febrile illness in Brazil. An estimated 500,000 cases of Oropouche fever have occurred in Brazil in ...
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Oropouche virus, of the family Bunyaviridae, genus Orthobunyavirus, serogroup Simbu, is an important causative agent of arboviral febrile illness in Brazil. An estimated 500,000 cases of Oropouche fever have occurred in Brazil in the last 30 years, with recorded cases also in Panama, Peru, Suriname and Trinidad. We have developed an experimental model of Oropouche virus infection in neonatal BALB/c mouse by subcutaneous inoculation. The vast majority of infected animals developed disease on the 5th day post infection, characterized mainly by lethargy and paralysis, progressing to death within 10 days. Viral replication was documented in brain cells by in situ hybridization, immunohistochemistry and virus titration. Multi-step immunohistochemistry indicated neurons as the main target cells of OROV infection. Histopathology revealed glial reaction and astrocyte activation in the brain and spinal cord, with neuronal apoptosis. Spleen hyperplasia and mild meningitis were also found, without viable virus detected in liver and spleen. This is the first report of an experimental mouse model of OROV infection, with severe involvement of the central nervous system, and should become useful in pathogenesis studies, as well as in preclinical testing of therapeutic interventions for this emerging pathogen.
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The emergence of multiple strains of bluetongue virus (BTV) and the recent discovery of Schmallenberg virus (SBV) in Europe have highlighted the fact that exotic Culicoides-borne arboviruses from remote geographic areas can enter ...
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The emergence of multiple strains of bluetongue virus (BTV) and the recent discovery of Schmallenberg virus (SBV) in Europe have highlighted the fact that exotic Culicoides-borne arboviruses from remote geographic areas can enter and spread rapidly in this region. This review considers the potential for this phenomenon to impact on human health in Europe, by examining evidence of the role of Culicoides biting midges in the zoonotic transmission and person-to-person spread of arboviruses worldwide. To date, the only arbovirus identified as being primarily transmitted by Culicoides to and between humans is Oropouche virus (OROV). This member of the genus Orthobunyavirus causes major epidemics of febrile illness in human populations of South and Central America and the Caribbean. We examine factors promoting sustained outbreaks of OROV in Brazil from an entomological perspective and assess aspects of the epidemiology of this arbovirus that are currently poorly understood, but may influence the risk of incursion into Europe. We then review the secondary and rarely reported role of Culicoides in the transmission of high-profile zoonotic infections, while critically reviewing evidence of this phenomenon in endemic transmission and place this in context with the presence of other potential vector groups in Europe. Scenarios for the incursions of Culicoides-borne human-to-human transmitted and zoonotic arboviruses are then discussed, along with control measures that could be employed to reduce their impact. These measures are placed in the context of legislative measures used during current and ongoing outbreaks of Culicoides-borne arboviruses in Europe, involving both veterinary and public health sectors.
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Oropouche virus (OROV) is a frequent cause of arboviral febrile disease in the Amazon. The present report describes studies done in two patients, one of them; the first OROV human case acquired outside of the Amazon, which have re...
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Oropouche virus (OROV) is a frequent cause of arboviral febrile disease in the Amazon. The present report describes studies done in two patients, one of them; the first OROV human case acquired outside of the Amazon, which have revealed for the first time the presence of OROV in peripheral blood leukocytes. This novel finding raises important issues regarding pathogenesis of human infections and may offer a new tool, for the rapid diagnosis of this neglected infection. J. Med. Virol. 89:1108-1111, 2017. (c) 2017 Wiley Periodicals, Inc.
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BACKGROUND: Oropouche fever virus is an important arbovirus associated with febrile disease that re-emerged in 2006 in several municipalities of Para State, Bragantina region, Amazon, Brazil, 26 years after the last epidemic. OBJE...
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BACKGROUND: Oropouche fever virus is an important arbovirus associated with febrile disease that re-emerged in 2006 in several municipalities of Para State, Bragantina region, Amazon, Brazil, 26 years after the last epidemic. OBJECTIVE: To investigate an Oropouche fever outbreak in this region. STUDY DESIGN: A serologic survey and prospective study of acute febrile cases were performed in Magalhaes Barata (urban and rural areas) and Maracana (rural area) municipalities. Serology (IgM-ELISA and hemagglutination-inhibition [HI]), virus isolation, RT-PCR and real-time-PCR were used to confirm Oropouche virus (OROV) as responsible for the febrile outbreaks. RESULTS: Real-time-PCR showed high titers of OROV in acute-phase serum samples from febrile patients. From 113 of 119 acutely febrile patients with paired serum samples, OROV infections was confirmed by serologic conversion (n=76) or high titers (n=37) for both HI and IgM-ELISA. Patients had a febrile disease characterized by headache, chills, dizziness, photophobia, myalgia, nausea, and vomiting. Females and children under 15 years of age were most affected. Nucleotide sequencing of six OROV isolates identified that genotype II was associated with the human disease epidemic. CONCLUSIONS: Oropouche fever, which has re-emerged in the Bragantina region in eastern Amazon 26 years after the last epidemic, is caused by genotype II, a lineage previously found only in Peru and western Brazil.
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French Guiana (FG), a French overseas territory in South America, is susceptible to tropical diseases, including arboviruses. The tropical climate supports the proliferation and establishment of vectors, making it difficult to con...
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French Guiana (FG), a French overseas territory in South America, is susceptible to tropical diseases, including arboviruses. The tropical climate supports the proliferation and establishment of vectors, making it difficult to control transmission. In the last ten years, FG has experienced large outbreaks of imported arboviruses such as Chikungunya and Zika, as well as endemic arboviruses such as dengue, Yellow fever, and Oropouche virus. Epidemiological surveillance is challenging due to the differing distributions and behaviors of vectors. This article aims to summarize the current knowledge of these arboviruses in FG and discuss the challenges of arbovirus emergence and reemergence. Effective control measures are hampered by the nonspecific clinical presentation of these diseases, as well as the Aedes aegypti mosquito's resistance to insecticides. Despite the high seroprevalence of certain viruses, the possibility of new epidemics cannot be ruled out. Therefore, active epidemiological surveillance is needed to identify potential outbreaks, and an adequate sentinel surveillance system and broad virological diagnostic panel are being developed in FG to improve disease management.
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Vector-borne diseases (VBDs) are important contributors to the global burden of infectious diseases due to their epidemic potential, which can result in significant population and economic impacts. Oropouche fever, caused by Oropo...
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Vector-borne diseases (VBDs) are important contributors to the global burden of infectious diseases due to their epidemic potential, which can result in significant population and economic impacts. Oropouche fever, caused by Oropouche virus (OROV), is an understudied zoonotic VBD febrile illness reported in Central and South America. The epidemic potential and areas of likely OROV spread remain unexplored, limiting capacities to improve epidemiological surveillance.To better understand the capacity for spread of OROV, we developed spatial epidemiology models using human outbreaks as OROV transmission-locality data, coupled with high-resolution satellite-derived vegetation phenology. Data were integrated using hypervolume modeling to infer likely areas of OROV transmission and emergence across the Americas.Models based on one-support vector machine hypervolumes consistently predicted risk areas for OROV transmission across the tropics of Latin America despite the inclusion of different parameters such as different study areas and environmental predictors. Models estimate that up to 5 million people are at risk of exposure to OROV. Nevertheless, the limited epidemiological data available generates uncertainty in projections. For example, some outbreaks have occurred under climatic conditions outside those where most transmission events occur. The distribution models also revealed that landscape variation, expressed as vegetation loss, is linked to OROV outbreaks.Hotspots of OROV transmission risk were detected along the tropics of South America. Vegetation loss might be a driver of Oropouche fever emergence. Modeling based on hypervolumes in spatial epidemiology might be considered an exploratory tool for analyzing data-limited emerging infectious diseases for which little understanding exists on their sylvatic cycles. OROV transmission risk maps can be used to improve surveillance, investigate OROV ecology and epidemiology, and inform early detection.
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Biting midges (Diptera: Ceratopogonidae) were collected at 16 periurban and rural sites around Iquitos, Peru, between 17 October 1996 and 26 May 1997. Culicoides paraensis (Goeldi), the principal vector of Oropouche virus, was the...
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Biting midges (Diptera: Ceratopogonidae) were collected at 16 periurban and rural sites around Iquitos, Peru, between 17 October 1996 and 26 May 1997. Culicoides paraensis (Goeldi), the principal vector of Oropouche virus, was the most commonly collected species (9,086 flies) with Culicoides insinuatus Wirth & Blanton second (7,229 flies). Although both species were collected at all sampling sites (linear distance surveyed approximate to25 km), C. paraensis dominated at northern collection sites (>90%), whereas C. insinuatus prevailed at southern collection sites (>60%). C. paraensis were collected from human sentinels at a constant rate throughout daylight hours, at similar rates during wet and dry months, and regardless of rainfall. Larval developmental substrates for C. paraensis included decaying platano (Musa X paradisiaca L. [Musaceae]) stems, stumps, flowers, fruits, and debris beneath platano trees as well as from soil beneath a fruiting mamay (Syzygium malaccense Merr. & Perry [Myrtaceae]) tree and organic-rich mud along a lake shoreline. C. insinuatus adults likewise emerged from decaying platano and organic-rich mud along a lake shoreline, but also from debris accumulated in the axils of aguaje (Mauritia flexuosa L. [Palmae]) fronds and decaying citrus fruit. Despite high numbers of biting adults near putative substrates, adults of neither species emerged from other decomposing plant material, soil, phytotelmata, or artificial containers. Because both species of biting midges emerged in high numbers from all parts of platano (ubiquitous in Iquitos), it will be challenging to control them through sanitation.
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Oropouche virus (OROV) causes an acute, systemic febrile illness, and in certain regions of South America, this represents the second most common human arboviral infection after dengue virus. A new real-time RT-PCR was developed f...
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Oropouche virus (OROV) causes an acute, systemic febrile illness, and in certain regions of South America, this represents the second most common human arboviral infection after dengue virus. A new real-time RT-PCR was developed for OROV and reassortant species. The new OROV rRT-PCR proved linear across 6-7 orders of magnitude with a lower limit of 95% detection of 5.6-10.8 copies/mu L. Upon testing dilutions of OROV and Iquitos virus reference genomic RNA, all dilutions with >10 copies/mu L were detected in both the OROV rRT-PCR and a comparator molecular assay, but the OROV rRT-PCR detected more samples with 收起
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Oropouche virus (ORO), family Bunyaviridae, is the second most frequent cause of arboviral febrile illness in Brazil. Studies were conducted to understand ORO entry in HeLa cells. Chlorpromazine inhibited early steps of ORO replic...
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Oropouche virus (ORO), family Bunyaviridae, is the second most frequent cause of arboviral febrile illness in Brazil. Studies were conducted to understand ORO entry in HeLa cells. Chlorpromazine inhibited early steps of ORO replication cycle, consistent with entry/uncoating. The data indicate that ORO enters HeLa cells by clathrin-coated vesicles, by a mechanism susceptible to endosomal acidification inhibitors. Transmission electron microscopy and immunofluorescence indicated that ORO associates with clathrin-coated pits and can be found in association with late endosomes in a time shorter than 1h.
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